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Multiband Network Feature Parameter Description
Copyright Huawei Technologies Co., Ltd. 2010. All rights
reserved.
No part of this document may be reproduced or transmitted in any
form or by any means without prior written consent of Huawei
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and other Huawei trademarks are trademarks of Huawei
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All other trademarks and trade names mentioned in this document
are the property of their respective holders.
Notice
The information in this document is subject to change without
notice. Every effort has been made in the preparation of this
document to ensure accuracy of the contents, but all statements,
information, and recommendations in this document do not constitute
the warranty of any kind, express or implied.
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BSS Multiband Network Contents
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iii
Contents 1 Introduction to This Document
.............................................................................................1-1
1.1 Scope
............................................................................................................................................
1-1 1.2 Intended Audience
........................................................................................................................
1-1 1.3 Change
History..............................................................................................................................
1-1
2 Overview
.....................................................................................................................................2-1
3 Technical Description
..............................................................................................................3-1
3.1 Multiband Network
Principles........................................................................................................
3-1
3.1.1 Overview of Multiband
Network............................................................................................
3-1 3.1.2 Cell
Reselection....................................................................................................................
3-1 3.1.3 Channel
Allocation................................................................................................................
3-1 3.1.4 Handover
..............................................................................................................................
3-1
3.2 Network Topologies
.......................................................................................................................
3-2 3.3 Overview of Enhanced Dualband Network
...................................................................................
3-5
3.3.1
Overview...............................................................................................................................
3-5 3.3.2 Channel
Allocation................................................................................................................
3-6 3.3.3 Handover
..............................................................................................................................
3-6
4 Engineering
Guidelines...........................................................................................................4-1
5 Parameters
.................................................................................................................................5-1
6
Counters......................................................................................................................................6-1
7 Glossary
......................................................................................................................................7-1
8 Reference Documents
.............................................................................................................8-1
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BSS Multiband Network 1 Introduction to This Document
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1 Introduction to This Document 1.1 Scope This document
describes the functions of and technologies regarding multiband
network and enhanced dual-band network, including cell reselection,
channel allocation, handover, and network topologies.
1.2 Intended Audience It is assumed that users of this document
are familiar with GSM basics and have a working knowledge of GSM
telecommunication.
This document is intended for:
z Personnel working on Huawei GSM products or systems z System
operators who need a general understanding of this feature
1.3 Change History The change history provides information on
the changes on the Multiband Network feature in different document
versions.
There are two types of changes, which are defined as
follows:
z Feature change Feature change refers to the change in the
Multiband Network feature of a specific product version.
z Editorial change Editorial change refers to the change in
wording or the addition of the information that was not described
in the earlier version.
Document Issues The document issues are as follows:
z 02 (2009-09-30) z 01 (2009-06-30)
02(2009-09-30) This is the second commercial release of
GBSS9.0.
Compared with issue 01 (2009-06-30) of GBSS9.0, issue 02
(2009-09-30) of GBSS9.0 incorporates the changes described in the
following table.
Change Type
Change Description Parameter Change
Feature change
None. None.
Editorial change
The structure of the document is optimized.
None.
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1 Introduction to This Document BSS
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Issue 02 (2009-09-30)
01(2009-06-30) This is the first commercial release of
GBSS9.0.
Compared with issue 01 (2009-04-30) of GBSS8.1, issue 01
(2009-06-30) of GBSS9.0 remains unchanged.
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BSS Multiband Network 2 Overview
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2 Overview A multiband network comprises the networks of
different frequency bands.
In a multiband network, the BSC should support the cell
reselection and handover of MSs between different frequency
bands.
The following network topologies are applicable to a multiband
network:
z Independent MSC network topology The network of each frequency
band has an independent MSC, and different networks are connected
through the MSCs.
z Co-MSC independent BSC network topology The network of each
frequency band has an independent BSC, and different networks are
connected through the same MSC.
z Co-BSC network topology The network of each frequency band has
independent cells, and these cells are connected to the same
BSC.
Table 2-1 describes the mapping between the frequency band and
the absolute radio frequency channel number (ARFCN).
Table 2-1 Mapping between the frequency band and the ARFCN
Frequency Band Uplink Frequency
Downlink Frequency ARFCN
Fl(n) = 890 + 0.2 x n Fu(n) = Fl(n) + 45 P-GSM900 band
890-915 MHz 935-960 MHz
1 n 124
Fl(n) = 890 + 0.2 x n 0 n 124
Fl(n) = 890 + 0.2 x (n - 1024)
Fu(n) = Fl(n) + 45
975 n 1023
E-GSM900 band
880-915 MHz 925-960 MHz -
Fl(n) = 890 + 0.2 x n 0 n 124
Fl(n) = 890 + 0.2 x (n - 1024)
Fu(n) = Fl(n) + 45
955 n 1023
R-GSM900 band
876-915 MHz 921-960 MHz -
Fl(n) = 1710.2 + 0.2 x (n - 512)
Fu(n) = Fl(n) + 95 DCS1800 band
1710-1785 MHz 1805-1880 MHz
512 n 885
Fl(n) = 1850.2 + 0.2 x (n - 512)
Fu(n) = Fl(n) + 80 PCS1900 band
1850-1910 MHz 1930-1990 MHz
512 n 810
GSM850 band
Fl(n) = 824.2 + 0.2 x (n - 128)
Fu(n) = Fl(n) + 45 128 n 251
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2 Overview BSS
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Frequency Downlink Band Uplink Frequency Frequency ARFCN
824-849 MHz 869-894 MHz
Two or more frequency bands can be combined into the same GSM
network. The most common combination is P-GSM900 with DCS1800 and
GSM850 with PCS1900. The combination between DCS1800 and PCS1900 is
not possible because frequencies in DCS1800 overlap with
frequencies in PCS1900.
The radio waves on different frequency bands have different path
loss characteristics. If the transmit power is the same, the
propagation distance of the radio wave from a low frequency band is
longer than that of the radio wave from a high frequency band. For
P-GSM900 and DCS1800, the number of frequencies available in
DCS1800 is three times the number of frequencies available in
P-GSM900, and thus DCS1800 can be used to provide additional
capacity. In a dualband network of P-GSM900 and DCS1800, the
characteristics of the two frequency bands can be optimally used to
expand the network capacity.
Huawei BSC supports the enhanced dualband network. The purpose
is to optimally share radio resources between P-GSM900 and DCS1800
and to enable the MS to measure the receive level of the two
frequency bands.
A cell can operate on multiple frequency bands, for example, a
co-BCCH cell. For details, see Co-BCCH Cell Parameter
Description.
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BSS Multiband Network 3 Technical Description
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3 Technical Description 3.1 Multiband Network Principles 3.1.1
Overview of Multiband Network In a multiband network, the MS and
BSS should provide additional functions to support cell reselection
and handover between cells of different frequency bands. These
functions are as follows:
z Broadcasting system information 2ter and 5ter z Indication of
the frequency band support capability of the MS z Measuring the
neighboring cells of different frequency bands and reporting the
measurement results
3.1.2 Cell Reselection When the cells operating on different
frequency bands are adjacent, cell reselection between these cells
is necessary.
To support cell reselection, the BSC needs to broadcast system
information 2ter, informing a multiband MS of the neighboring cells
on the frequency bands rather than the serving band. Then, the MS
measures the receive level of the neighboring cells and decides
whether to reselect a neighboring cell according to the cell
reselection algorithm.
3.1.3 Channel Allocation In a co-BCCH cell, in a cell of the
enhanced dualband network, or in a cell that is configured with
frequencies in P-GSM900, E-GSM900, and R-GSM900, the BSC allocates
a channel to an MS only when the MS supports the corresponding
frequency band. For example, there is a frequency with ARFCN 975
available in E-GSM900. If the MS supports only P-GSM900, the BSC
does not allocate ARFCN 975 to the MS. If the MS supports E-GSM900,
the BSC may allocate ARFCN 975 to the MS.
The Classmark 3 information element (IE) specifies the frequency
band support capability of the MS. From the Classmark 3 IE, the BSC
obtains the frequency band support capability of the MS so as to
allocate an appropriate channel. If the BSC does not obtain the
Classmark 3 IE from the MS during channel allocation, the BSC
regards that the MS supports only the frequency band that is
compatible with the BCCH frequency. In this case, the BSC allocates
the MS a channel on the frequency band compatible with the BCCH
frequency.
The switch ECSC should be turned on so that the BSC can obtain
the frequency band support capability of the MS at the earliest.
After the switch is turned on, the BSC broadcasts system
information 3, instructing the MS to report the Classmark 3 IE at
the earliest after access. In this way, the MS need not wait for
the Classmark Enquiry message from the network before reporting the
Classmark 3 IE.
The channel allocation method described above is applicable only
during the assignment phase. During the immediate assignment phase,
an SDCCH compatible with the BCCH frequency is assigned
preferentially.
3.1.4 Handover When the MS moves from one cell on a frequency
band to another cell on a different frequency band during a call, a
handover is performed if the MS supports multiple frequency bands.
To support the handover, the BSC and MS should provide the
following functions:
z System information broadcasting
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During a call, the BSS informs the MS of the information about
neighboring cells through system information 5 and 5bis. If any
neighboring cell operates on a frequency band rather than the
serving band, the BSS needs to broadcast system information 5ter.
System information 5ter carries the information about the
neighboring cells of other frequency bands.
z Multi-band report After receiving system information 5, 5bis,
and 5ter, the MS measures the signal strength of the neighboring
cells specified in the system information and then sends the
measurement results to the BSS through measurement reports (MRs).
One MR contains the information about a maximum of six neighboring
cells. If all the neighboring cells measured by the MS operate on
the same frequency band, the MS reports the measurement results of
the six strongest neighboring cells to the BSS. If the neighboring
cells measured by the MS operate on different frequency bands, the
number of neighboring cells on other frequency bands reported by
the MS is specified by the parameter Multi-band report. The setting
of this parameter is as follows: If Multi-band report is set to 0,
the MS reports the six strongest neighboring cells irrespective of
the
frequency bands used in the cells. If Multi-band report is set
to 1, the MS reports the strongest neighboring cell on a
different
frequency band to the BSC. The remaining positions in the MR are
used for the neighboring cells of the serving band. If Multi-band
report is set to 2, the MS reports the two strongest neighboring
cells on different
frequency bands to the BSC. The remaining positions in the MR
are used for the neighboring cells of the serving band. If
Multi-band report is set to 3, the MS reports the three strongest
neighboring cells on different
frequency bands to the BSC. The remaining positions in the MR
are used for the neighboring cells of the serving band. The BSC
informs the MS of the value of Multi-band report through system
information 2ter and 5ter.
After receiving the MR from the MS, the BSC decides whether a
handover should be performed. For details of the handover
algorithms and procedures, see the handover feature.
3.2 Network Topologies There are three types of network
topologies for a multiband network: independent MSC, co-MSC
independent BSC, and co-BSC. The first two types are referred to as
independent network topology, and the third type is referred to as
hybrid network topology.
Independent MSC Network Topology In an independent MSC network
topology, the GSM850 band, GSM900 band, DCS1800 band, and GSM1900
band use different MSCs. Figure 3-1 shows the independent MSC
network topology in which the commonly used GSM900 band and DCS1800
band are applied.
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BSS Multiband Network 3 Technical Description
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Figure 3-1 Independent MSC network topology
MS
BTS
BTS
BSC
OMC
SMC
MSC/VLR 1
BTS
BTS
BSCMS MSC/VLR 2
EIR
HLR/AUC
GSM900M
DCS1800M
The characteristics of independent MSC network topology are as
follows:
z No impact on the existing network z Convenient for network
planning and data configuration, thus facilitating network
deployment z Heavy load of signaling links due to frequent
inter-BSC handovers and location updates z Meeting long-term
capacity expansion requirements z Convenient for network management
and service development z Requiring cooperation between equipment
from different vendors z Big investment of network deployment at an
early stage, but lowest average investment per user
With all these features, the independent MSC network topology is
more efficient than the hybrid network topology in the long
run.
Co-MSC Independent BSC Network Topology In a co-MSC independent
BSC network topology, the GSM850 band, GSM900 band, DCS1800 band,
and GSM1900 band use the same MSC but different BSCs. Figure 3-2
shows the co-MSC independent BSC network topology in which the
commonly used GSM900 band and DCS1800 band are applied.
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Figure 3-2 Co-MSC independent BSC network topology
DCS1800M
GSM900M
MS
BTS
BTS
BSC1
OMC
SMC
BTS
BTS
BSC2MS
MSC/VLR
EIR
HLR/AUC
The characteristics of co-MSC independent BSC network topology
are as follows:
z Possible impact on the existing network. z Re-planning NSS is
required, and network deployment is somewhat difficult. z
Inconvenient for capacity expansion and network evolution. z Small
investment of network deployment at an early stage, and lower
average investment per user. z Competition among equipment vendors
is introduced, which helps reduce equipment investment and
improve the quality of service (QoS). z Multiple BSCs cooperate
with each other, and network security is guaranteed.
Co-BSC Network Topology In a co-BSC network topology, the GSM850
band, GSM900 band, DCS1800 band, and GSM1900 band use the same BSC,
or multiband BTSs are connected to the same BSC. Figure 3-3 shows
the co-BSC network topology in which the commonly used GSM900 band
and DCS1800 band are applied.
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BSS Multiband Network 3 Technical Description
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Figure 3-3 Co-BSC network topology
BSC2
BSC1MS
BTS
BTS OMC
SMCBTS
BTS
MSC/VLR
EIR
HLR/AUC
BTS
BTSMS
DCS1800MGSM900M GSM900M/DCS1800M
The characteristics of co-BSC network topology are as
follows:
z Possible huge impact on the existing network. The impact is
inversely proportional to the capacity of the BSC.
z Re-planning NSS and BSS is required, and network deployment is
difficult. z Inconvenient for capacity expansion and network
evolution. z Inconvenient for service deployment. z Competition
among equipment manufacturers cannot be introduced. It is difficult
to cut down
investment and improve QoS.
3.3 Overview of Enhanced Dualband Network 3.3.1 Overview The
enhanced dualband network is an improvement on the existing
dualband network. It is implemented as follows: physically, two
single-band cells are located at the same layer and have the same
priority but different coverage areas; logically, the two cells
serve as neighboring cells of each other and form a cell group,
namely, one overlaid cell and one underlaid cell. The enhanced
dualband network algorithm enables channel sharing and load
balancing between the two cells in the cell group.
For details about cell layers and priorities, see Cell Layer and
Cell Priority in Fast-Moving Micro Cell Handover.
The handover decision for the overlaid cell and the underlaid
cell in the cell group is based on the MR. Figure 3-4 shows the
cell structure of the enhanced dualband network.
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Figure 3-4 Cell structure of the enhanced dualband network
Distance
Overlaid cell A
Cell group
Underlaid cell B
Cell group
Overlaid cell A
Underlaid cell B
3.3.2 Channel Allocation When an MS attempts to access the
enhanced dualband network, the BSC allocates a channel to the MS
according to the following principles:
z When the MS in the underlaid cell attempts to access the
network, the BSC should determine whether the receive level of the
MS is higher than or equal to the minimum access level of the
overlaid cell if the load in the underlaid cell is higher than UL
Subcell General Overload Threshold. If the receive level of the MS
is higher than or equal to the minimum access level of the overlaid
cell, and the load in the overlaid cell does not exceed the
specified threshold, the BSC assigns the MS a channel in the
overlaid cell and initiates a directed retry procedure to hand over
the MS to the overlaid cell. Otherwise, the BSC assigns a channel
in the underlaid cell to the MS. If congestion occurs in the
underlaid cell, the queuing procedure and preemption procedure
are
initiated. If no channel is available in the underlaid cell, the
MS performs cell reselection.
z When the MS in the overlaid cell attempts to access the
network, the BSC assigns the MS a channel in the underlaid cell
preferentially if the load in the underlaid cell is lower than UL
Subcell Lower Load Threshold. Otherwise, the BSC assigns a channel
in the overlaid cell to the MS. If congestion occurs in the
overlaid cell, the queuing procedure and preemption procedure
are
initiated. If no channel is available in the overlaid cell, the
MS performs cell reselection.
3.3.3 Handover The handover algorithms for an enhanced dualband
network are of two types: handover algorithm I and handover
algorithm II. For details, see Enhanced Dual-Band Network Handover
of Handover Decision Based on Handover Algorithm I and Enhanced
Dual-Band Network Handover of Handover Decision Based on Handover
Algorithm II in the Handover feature.
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BSS Multiband Network 4 Engineering Guidelines
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4 Engineering Guidelines The principles of distributing traffic
between different frequency bands in a multiband network are as
follows:
z In the initial stage of network deployment, the DCS1800 cells
should absorb traffic as much as possible.
z In hot spots, the DCS1800 network should provide continuous
coverage. z When the number of multiband MSs reaches a certain
level, different frequency bands should share
the traffic to reduce handovers and improve QoS.
The telecom operator can implement different traffic control
strategies by adjusting related parameters in real time. The
traffic control strategies also depend on the MS state. The
detailed strategies are as follows:
z When an MS performs cell selection after being powered on or
performs cell reselection in standby state, system parameters can
be set in a way that a DCS1800 cell has a high priority. Therefore,
the DCS1800 cell tends to be the serving cell of a multiband MS,
and the MS tends to camp on the DCS1800 cell before a call is
established.
z During a call establishment procedure, the traffic
distribution can be adjusted through directed retry. z During an
ongoing call, the traffic should be distributed to the DCS1800 cell
of low layer and high
priority as much as possible. z Handovers can be performed
between the cells of different frequency bands for optimal
traffic
distribution.
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BSS Multiband Network 5 Parameters
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5 Parameters This chapter describes the parameters related to
multiband network.
For the meaning of each parameter, see Table 5-1. For the
default value, value ranges, and MML commands of each parameter,
see Table 5-2.
Table 5-1 Parameter description (1)
Parameter Description
ECSC
The early classmark sending control (ECSC) parameter specifies
whether the MSs in a cell use early classmark sending. After a
successful immediate assignment, the MS sends additional classmark
information to the network as early as possible. The additional
classmark information mainly contains the CM3 (classmark 3)
information. The CM3 (classmark 3) information contains the
frequency band support capability of the MS (used for the future
channel assignment), power information about each frequency band
supported by the MS (used for the handover between different
frequency bands), and encryption capability of the MS.
Multi-band report
Used for requesting the MS to report the measurement information
of neighboring cells in multiple frequency bands. This parameter is
carried in the system information 2ter and 5ter.
UL Subcell General Overload Threshold
When the load of the underlay subcell is higher than this
parameter, some of the calls in the underlay subcell will be
switched to the overlay subcell, and channels in the overlay
subcell will be preferentially assigned to calls initiated in the
underlay subcell as well.
UL Subcell Lower Load Threshold
When the load of the underlay subcell is lower than this
parameter, some of the calls in the overlay subcell will be
switched to the underlay subcell, and channels in the underlay
subcell will be preferentially assigned to channel requests
initiated in the overlay subcell as well.
Table 5-2 Parameter description (2)
Parameter Default Value GUI Value Range
Actual Value Range
Unit MML Command Impact
ECSC NO
NO(No), YES(Yes) NO, YES None
SET GCELLCCBASIC (Optional) Cell
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GUI Actual Default MML Parameter Value Value Range Value Unit
Impact Command Range
Multi-band report 0 0~3 0~3 None
SET GCELLCCBASIC (Optional) Cell
UL Subcell General Overload Threshold 80 0~100 0~100
per cent
SET GCELLHOEDBPARA (Optional) Cell
UL Subcell Lower Load Threshold 50 0~100 0~100
per cent
SET GCELLHOEDBPARA (Optional) Cell
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BSS Multiband Network 6 Counters
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6 Counters For the counters, see the BSC6900 GSM Performance
Counter Reference.
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BSS Multiband Network 7 Glossary
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7 Glossary For the acronyms, abbreviations, terms, and
definitions, see the Glossary.
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BSS Multiband Network 8 Reference Documents
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8 Reference Documents z 3GPP TS 04.08: "Mobile radio interface
layer 3: specification" z 3GPP TS 05.05: "Digital cellular
telecommunication system (Phase 2+); Radio transmission and
reception" z 3GPP TS 05.08: "Digital cellular telecommunications
system (Phase 2+); Radio subsystem link
control" z BSC6900 Feature List z BSC6900 Optional Feature
Description z GBSS Reconfiguration Guide z BSC6900 GSM Parameter
Reference z BSC6900 GSM MML Command Reference z BSC6900 GSM
Performance Counter Reference
1 Introduction to This Document 1.1 Scope 1.2 Intended Audience
1.3 Change History 2 Overview 3 Technical Description 3.1 Multiband
Network Principles 3.1.1 Overview of Multiband Network 3.1.2 Cell
Reselection 3.1.3 Channel Allocation 3.1.4 Handover
3.2 Network Topologies 3.3 Overview of Enhanced Dualband Network
3.3.1 Overview 3.3.2 Channel Allocation 3.3.3 Handover
4 Engineering Guidelines 5 Parameters 6 Counters 7 Glossary 8
Reference Documents